I started on supporting enable/disable host sensors.

Everythings is fine until I add code to monitor host status as below.

bool MainLoop::isHostOn(void)
{
    char buff[128];

    if (!powerMatch)
    {
        log<level::ERR>("Power Match Not Created");
    }
    sprintf(buff, "isHostOn powerStatusOn: %d\n",powerStatusOn);
    log<level::INFO>(buff);
    return powerStatusOn;
}

std::shared_ptr<sdbusplus::bus::match::match> 
    MainLoop::startHostStateMonitor(void) {
    return std::make_shared<sdbusplus::bus::match::match>(
    *conn,
    "type='signal',interface='org.freedesktop.DBus.Properties',"
    "member='PropertiesChanged',arg0='xyz.openbmc_project.State.Host'",
    [](sdbusplus::message::message &msg) {
    std::string interfaceName;
    boost::container::flat_map<std::string, std::variant<std::string>>
        propertiesChanged;
    try {
        msg.read(interfaceName, propertiesChanged);
    } catch (std::exception &e) {
        log<level::ERR>("Unable to read host state\n");
        return;
    }
    // We only want to check for CurrentHostState
    if (propertiesChanged.begin()->first != "CurrentHostState") {
        return;
    }
    auto findState = propertiesChanged.find(powProperty);
    if (findState != propertiesChanged.end())
    {
        powerStatusOn = boost::ends_with(
            std::get<std::string>(findState->second), "Running");
    }
    powerMatch = true;
    });
}

void MainLoop::read()
{
    // TODO: Issue#3 - Need to make calls to the dbus sensor cache here to
    //       ensure the objects all exist?

    /* Host changed state from On to Off */
    if (!isHostOn() && (lastPowerState == HOST_ON ||
            lastPowerState == HOST_NA)) {
        removeHostSensors();
        lastPowerState = HOST_OFF;
    }

    /* Host changed state from Off to On */
    if (isHostOn() && lastPowerState == HOST_OFF) {
        addDroppedHostSensors();
        lastPowerState = HOST_ON;
    }

When build openBMC I got error:

tmp/work/arm1176jzs-openbmc-linux-gnueabi/phosphor-hwmon/1.0+gitAUTOINC+5906173aec-r1/recipe-sysroot/lib/libpthread.so.0: error adding symbols: DSO missing from command line

| collect2: error: ld returned 1 exit status

| make[2]: *** [Makefile:643: phosphor-hwmon-readd] Error 1

It seems I need adding the threads lib to defend lib.

Any suggestion to add threads lib to build configuration?

Thanks.

Thu.

On Wed, Oct 21, 2020 at 11:54 PM Thu Ba Nguyen <tbnguyen1985@gmail.com> wrote:

Hi Vijay,

I took a look on entity-manager and openbmc source.
Don't have many companies using entity-manager model to support sensors.

Regards
Thu Nguyen.

On Wed, Oct 21, 2020 at 7:15 AM Vijay Khemka <vijaykhemka@fb.com> wrote:

From: openbmc <openbmc-bounces+vijaykhemka=fb.com@lists.ozlabs.org> on behalf of Thu Ba Nguyen <tbnguyen1985@gmail.com>
Date: Monday, October 19, 2020 at 11:23 AM
To: Ed Tanous <ed@tanous.net>
Cc: OpenBMC Maillist <openbmc@lists.ozlabs.org>
Subject: Re: Enable/Disable some sensors when Host On/Off

Hi Ed Tanous,

> Thanks for your info,

> But in your platform we are using phosphor-hwmon to manage sensors.

> We don't use entity-manager.

> As I knew we can't use both entity-manager and phosphor-hwmon for one project.

You can use both but for different sensors. You can decide what sensors to configure

via EM/dbus-sensors and which one for phosphor-hwmon.

Regards

Thu Nguyen.